Humidity is set to rise in both Abu Dhabi and Dubai on Thursday as temperatures top 40°C again.
The National Centre of Meteorology forecasts humidity levels to reach up to 85 per cent in Dubai and 75 per cent in the capital.
The mercury will peak at 41°C in Abu Dhabi and 40°C in Dubai, the weather centre said in its daily bulletin.
Al Ain is set to record the hottest temperatures of the day, at 45°C.
The NCM said it would be particularly humid during the evening and into Friday morning.
There is a prospect of mist forming in northern parts of the country.
Winds will be light to moderate throughout Thursday.
Temperatures are set to drop on Friday, largely in coastal areas, with a chance of fog and mist in the north.